I realize this is a question for Bs, but I don't know when he will be online again.

On a locking nut guitar WITHOUT a string tree bar, are HAP machine heads still necessary?

My take on that is that you still need some angle across the nut, even with a locking nut because you're tuning the guitar with the nut unlocked. My big pet peeve is seeing people's fine tuners bottomed out, I am secretly judging them.
You could get there without a staggered set of tuners or adjustable posts, you might want to run a fender style string tree if the B and E strings get way out of line on you.

Unless strings are squarely in their groove, locking them down will make them go out of tune (almost always sharp). I always loved the floyd string tree bar setup simply because they gave great angle across the nut. I guess the one exception I can think of is the goofy locking nut behind a normal nut setup, and that would mean extra great tension across the actual nut because you'd mount it lower down the carve.

I realize this is a question for Bs, but I don't know when he will be online again.

On a locking nut guitar WITHOUT a string tree bar, are HAP machine heads still necessary?

Is the headstock an angled one too? If not, you'd definitely need them, but if it is, you might not. As far as I can remember, you can have a six string with a non-angled headstock and the HAPs would be enough (basically the same style as the MB-1s for the headstock). With a seven string, you wouldn't get enough tension on the seventh string even with HAPs so you need some angle on the headstock for that. So your answer kind of depends on the guitar.

If it's a six string and the headstock is angled then you probably don't need the HAPs (like most trem guitars) but they would help to add a bit more tension. If the headstock isn't angled then you'd need the HAPs to provide some tension anyway. 7 string, without a bar you'd need both unless there's enough of an angle on the headstock already. Some headstocks have a bigger or smaller angle than others I think. Hope that makes sense. Typing on my phone so it might be a bit of a mess.

On the point above, I have both a bit of an angle and the HAPs on mine and I notice no difference in pitch whatsoever between when the locking nut is or isn't on when I'm tuning. That might be the ZR bridge though, and the extra string does make it pretty firm anyway. That's the old tuning stability vs ease of trem use debate though, haha!

I guess I'll need to have one of these string retainers installed if I want to use these machine heads. Not doing it myself though, considering I screwed up the placement of the string tree on the strat build assembly I did

I guess I'll need to have one of these string retainers installed if I want to use these machine heads. Not doing it myself though, considering I screwed up the placement of the string tree on the strat build assembly I did

You're talking to a guy that drilled through a headstock for the pin on some new locking tuners. Talk about That's hands down my worst moment working on guitars.

You're talking to a guy that drilled through a headstock for the pin on some new locking tuners. Talk about That's hands down my worst moment working on guitars.

Sounds like something I would do.

But as far as I can remember, I haven't done any serious damage while working on guitars...not including the "attempt" at routing that strat copy for a bridge humbucker when I was around 17. EVH himself would have done a better job!

It's just minor things that could be better.

In case you all are wondering what I'm going on about. I'm wanting to replace the standard chrome machine heads on my copper guitar with these, but they're only in non-HAP as far as I can tell.

That you in the comments? I still don't know who everyone is on there!

And thanks - It probably could use the string retainer to make things a bit easier, but it only goes slightly sharp on the high E and B strings when clamping down. Having said that, I did put some extra winds on the posts, which might have helped.

That you in the comments? I still don't know who everyone is on there!

And thanks - It probably could use the string retainer to make things a bit easier, but it only goes slightly sharp on the high E and B strings when clamping down. Having said that, I did put some extra winds on the posts, which might have helped.

Sorry Bs, I know this contradicts everything you believe in.

yessir, that was me. eh_D = Eddie. My stealth machine should be here by end of the week